For the purposes of the present patent application, an electrical terminal device is an electrical component for firm or permanent connection to a cable and configured to releasably connect with a mating component. The mating component of the terminal device is called the terminal receptacle and the mating component of the terminal receptacle is called the terminal device.
In electrical engineering and electronics, a large number of terminal devices and associated mating components, in particular a large number of very different plug connectors and plug receptacles are available. These serve to transmit electrical power and/or electrical signals with the widest possible range of voltages, currents, frequencies and data rates. To prevent the emission or coupling-in of electromagnetic interference, the complementary terminals may be provided with single or multiple shielding in accordance with the cables or other transmission elements connected therewith. To protect against damp, dusty, or chemically aggressive environments, terminal devices and terminal receptacles comprise a very wide range of sealing elements. Screw fittings or latch fittings may serve to prevent separation of terminal devices and terminal receptacles. The actual current-carrying connections may be produced, for example, by a plug-in connection or by screwing a cable lug crimped onto the cable together with a screwable terminal or contact provided in the terminal receptacle. Due to the extremely wide range of applications and conditions of use, a wide variety of optimized complementary terminal elements are available.
A relatively new field of use for terminal devices and terminal receptacles is the transmission of drive power in an electrically driven motor vehicle. This drive power is transmitted between an energy storage means, for example a storage battery, a fuel cell, a generator, or other energy source, a power converter and one or more drive motors in one direction or alternating in both directions. In particular, between the power converter and the drive motor(s), the drive power may be transmitted in pulse width-modulated manner and thus with a high A.C. component. Cables or leads with shielding are used to prevent the emission of electromagnetic interference signals.
Motor vehicles with an electromotive drive existed until recently only in the form of prototypes or short run models. For this reason, the terminal devices and terminal receptacles which have been used in the power transmission area are those which are readily available but are distinguished for the most part by a robust but also very complex structure. These terminal devices and terminal receptacles are therefore complex and expensive to produce and assemble.
With electrically driven motor vehicles moving into the realms of series and mass production, the demands placed on the terminals in the power transmission area are also changing. They not only have to be robust and ensure long-term, malfunction-free functioning over the entire life of the motor vehicle, but also have to be simple and cheap to produce and assemble. One of these new demands is the desire to avoid the very high plug-in forces which arise with the plug-in connectors used hitherto due to the large lead cross-sections and the associated contact sizes. These assembly forces cannot be sufficiently reduced by assembly aids such as levers. In addition, assembly aids require a very large structural space.
An object of the present invention is to provide a completely sealed (shield and conductor) terminal device for a shielded cable, which allows simple, cheap production and reliable, low-force assembly on connection with a terminal receptacle.